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Finding the Fourth Proportional to 280.48, 420.72 and 136.30

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Solution

The fourth proportional to 280.48, 420.72 and 136.30 is: 204.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.48 : 420.72 = 136.30 : x
  2. Step 2: Convert to fraction form
    280.48/420.72 = 136.30/x
  3. Step 3: Cross multiply
    280.48x = 420.72 × 136.30
  4. Step 4: Simplify right side
    280.48x = 57,344.14
  5. Step 5: Solve for x
    x = 57,344.14/280.48
  6. Step 6: Final answer
    x = 204.45

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.